1   Introduction

   1.1  Compatibility

   Compatible with FrSky two way telemetry modules: DFT, DJT, DHT, DHT-U

   1.2  Specifications

   Dimension: 40*22.5*6mm

   Weight: 5.8g / 5g (naked)

   Operating Voltage Range: 3.5V-10.0V

   Operating Current: 60mA

   Operating Range: Full Range (>1.5km)

   Resolution: 3072 (>11bit)

   1.3  Features

       1)  Firmware upgradeable;

       2)  One external analog telemetry port and one digital data-stream port (connect to FrSky Sensor Hub FSH-01);

       3)  CPPM output and RSSI (PWM) - If CH3 and CH4 are connected by a jumper, CH1 will output CPPM for CH1~CH8, and CH2 will output  RSSI (PWM);

       4)  Lighter weight and physically smaller than D8R-IIplus & D6FR;

       5)  Alarm warning on low voltage, poor reception, etc.

2   Set up

   2.1  Bind procedure

       1)  Ascertain that the transmitter is in the PPM mode. Turn the transmitter off.

       2)  Turn on the transmitter while holding the F/S button on the transmitter module (Ensure that both switches on the transmitter module are OFF when using this receiver in the two way mode). Release the button. The RED LED on the transmitter module will flash, indicating the transmitter is ready to bind to the receiver.

       3)  Connect battery to the receiver while holding the F/S button on the receiver. The LED on the receiver will flash, indicating the binding process is completed. Turn off both the transmitter and receiver.

       4)  Turn on the transmitter and connect the battery to the receiver. The GREEN LED on the receiver will indicate the receiver is receiving commands from the transmitter. The receiver/transmitter module binding will not have to be repeated, unless one of the two is replaced.

   2.2  Range check

   A pre-flight range check should be done before each flying session. Reflections from nearby metal fences, concrete buildings, or trees can cause loss of signal both during the range check and during flight.

   The following steps are to be followed to perform the range check of the model before flight:

       1)  Place the model at least 60cm (two feet) above non-metal contaminated ground (e.g. on a wooden bench).

       2)  The receiver antennas should be separated in the model, and not touching the ground.

       3)  Place the antenna of the transmitter in a vertical position.

       4)  Turn on the transmitter and receiver, press the F/S button of the transmitter for 4 seconds to enter range check mode, the RED LED of the transmitter module will be off, GREEN LED will flash rapidly, and the BEEPER will sound. The effective distance will be decreased to 1/30 of full range.

       5)  Walk away from the model while simultaneously operating the controls on the transmitter, confirming that all controls operate normally.

       6)  Press the F/S button for 1S-4S to exit range check mode, RED LED will be back on, indicating normal operation is back.

   2.3  Setting failsafe

   Failsafe is a useful feature in which all controls move to a preset position whenever the control signal is lost for a period of time. D4R-II supports failsafe function for all channels.

   Follow the steps below to set failsafe positions for each channel:

       1)  Bind the receiver first and turn on both the transmitter and receiver;

       2)  Move the controls to the desired failsafe position for all channels;

       3)  Press briefly the F/S button of the receiver (less than 1 second). The GREEN LED of the receiver will flash twice, indicating the failsafe position has been set in the receiver.

   To disable the failsafe function, re-bind the receiver.

   2.4  LED status

If CH3 and CH4 are connected by a jumper, CH1 will output output CPPM for CH1~CH8, and CH2 will output RSSI(PWM).